The invention relates to a system for supporting rollable objects. The invention also relates to a supporting part for use in such a system and to a rail for use in such a system.
Systems for supporting rollable objects are generally known, for instance for storing rolls of steel plate or foils. Characteristic of systems for supporting rollable or tiltable objects is that, optionally in addition to vertical support, they offer support to an object in horizontal direction, in order to prevent tilting and/or rolling away. The known systems comprise several supporting parts and rails, the supporting parts serving for supporting the object while the rails are used for positioning the supporting parts.
One of the requirements a system for supporting rollable objects needs to meet is that it does not seriously damage the surface of the object to be supported.
Known are supporting parts provided with a supporting surface for supporting an object, and a contact surface for transmitting the forces to the rail. The supporting part is wedge-shaped in that the supporting surface and the contact surface are at a mutual angle. An advantage of an oblique supporting surface is that it can absorb the forces both in the vertical and in the horizontal direction. The contact surface is provided with a toothing for positioning the supporting part in the rail. Such supporting parts, in any case their supporting surfaces, are typically manufactured from plastic. The plastic used has a relatively low E-modulus so that, when loaded, the supporting part conforms to some extent to the contour of the object to be supported. As a result, the chance of peak loads on the object to be supported, and, hence, the chance of damage to this object decreases.
These known supporting parts are arranged in a steel rail. This rail has an elongated shape, and comprises a metal U-section, placed with the open side upwards. In the U-section, cross partitions are welded. The supporting parts are dimensioned such that width-wise, they fit exactly in the rail, while the toothing fits over the cross partitions into the U-section.
For supporting, for instance, a roll of steel plate, two or more rails are arranged parallel, side-by-side, perpendicular to the longitudinal axis of the object to be supported. Per rail, two supporting parts are arranged with the oblique sides facing each other. The supporting parts thus form a recess, as it were, in which a roll or cylinder remains, by itself, at the deepest point. In the direction parallel to the longitudinal direction of the rail, the supporting parts are held in place by the cross partitions, and, in a direction at an angle to the longitudinal direction of the rail, by the walls of the U-section.
The weight of the roll is transmitted via the supporting parts to the rail, which bears on the base. As the roll bears on the oblique supporting surfaces of the supporting parts, also, a force in the horizontal direction is applied to the supporting parts, parallel to the longitudinal direction of the rail. These forces are transmitted via the cross partitions of the rail, and are opposite for two supporting parts placed in the same rail. Thus loaded, the supporting parts are pressed apart, as it were. However, as the supporting parts are interconnected via the rail, the opposing forces eliminate one another and the system as a whole is in rest. Hence, the blocks and the rail need not be solidly anchored to the base.
A drawback of such a system is that the edges of the metal rail can easily damage the relatively soft plastic, and/or can bend easily when they are inadvertently loaded in an incorrectly manner. This may for instance happen when an object is placed on the rail instead of on a supporting part. Further, welding a large number of cross partitions in a rail is labour-intensive and, hence, an expensive matter.
From international patent application WO 97/44220, another system for supporting rollable objects is known, which comprises one or more plastic connecting elements (or rails) on which two wedge-shaped plastic supporting parts can be placed.
The rails are formed as toothed racks, provided with angular teeth. The wedge-shaped supporting parts are provided, at the underside, with a groove so that they can be placed over the rail. The supporting parts are connected to the rail via toothings provided on the top of the grooves, which fit into the teeth of the rails. A drawback of the system known from this PCT publication is that the toothing deforms easily when loaded. The toothing of the rails must be widely dimensions in order to absorb the forces from the supporting parts without deforming. However, as a result, the toothing becomes relatively coarse. The coarse toothing does not allow precise positioning of the supporting parts related to the object to be supported.